Mount Prospect, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

883
FXUS63 KLOT 061138
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
638 AM CDT Mon Jul 6 2026

.KEY MESSAGES...

- Moderate swim risk at southern Lake Michigan beaches
  through tonight due to persistent breezy onshore winds and
  increased rip current threat.

- Drier and more seasonable conditions expected through
  Wednesday before shower and thunderstorm chances return late
  week.

&&

.DISCUSSION...
Issued at 237 AM CDT Mon Jul 6 2026

A mid-level ridge axis is in the process of building into the
upper Midwest and western Great Lakes this morning and this will
bring us some tranquil weather to start the week. However, the
700 mb low that brought us the scattered showers yesterday has
not made as much eastward progress as guidance suggested
24-hours ago. In fact, nighttime microphysics imagery shows this
low sitting over southeast lower MI and northern OH. Attached
to this low is a modest baroclinic zone stretching from the low
southwestward into eastern MO and this axis looks to be the spot
for isolated to widely scattered showers and thunderstorms to
develop today. Given that the baroclinic zone is south of our
area, the expectation is for most of northeast IL and northwest
IN to remain dry but a stray shower (maybe with an associated
lightning strike) cannot be ruled out near and south of a
Paxton, IL to Rensselaer, IN line.

Aside from the non-zero rain chance, today will feature partly
to mostly sunny skies with temperatures once again in the low to
mid-80s inland with mid to upper 70s expected near the lake.
Persistent northeast winds will become breezy this afternoon
(localized gusts around 20 mph) which will maintain 2 to 4 feet
waves at area beaches through tonight. Waves of this magnitude
will continue to lead to an increased rip current risk
especially at unprotected beaches. So if planning to head to the
beach make sure bring the life jacket and if conditions are too
hazardous for your comfort stay out of the water.

Dry weather will continue into Tuesday as the aforementioned
ridge remains solidly overhead. While winds will be notably
lighter (speeds around 5-10 mph) they will still be out of the
east-northeast which will continue to support locally cooler
temperatures near the immediate lakeshore (in the mid to upper
70s). Elsewhere temperatures will be warmer in the mid-80s.

Heading into Wednesday, the mid-level ridging will begin to
weaken as a shortwave trough traverses across the northern
Plains and into the Upper Midwest. At the same time, the closed
low (that is forecast to form from the subtle shortwave diving
across MO currently) will begin to lift northward from southern
MO towards the Ohio River Valley. Recent guidance trends are
showing that northern stream shortwave may arrive later and thus
keep the rain potential at bay until either late Wednesday
night or Thursday. In fact, forecast soundings do show some
decent capping in place across northern IL and northwest IN on
Wednesday which should further limit any shower or storm
development. So the current forecast will feature dry conditions
for Wednesday with temperatures a tad warmer then Tuesday with
highs in the mid to upper 80s areawide (including near the
lakeshore).

Shower and thunderstorm chances will be on the increase for
Thursday as the aforementioned northern shortwave and closed low
begin to phase over the southern Great Lakes and push a frontal
zone into northern IL and northwest IN. These features should
result in widespread showers and thunderstorms through Thursday
night, but the modest wind shear looks to keep any severe threat
low at this time. However, the presence of a slow moving
boundary and relatively weak shear/mid-level flow may set up the
potential for slow moving/training showers and storms which
could result in periods of heavy rainfall and perhaps even some
localized flooding. Right now confidence is low on if training
will occur and if it does where the heaviest rain will
materialize but this is a period that will be monitored closely
over the coming days.

Additional periods of showers and thunderstorms are expected
Friday and into the weekend as shortwaves continue to pass
through northern IL and northwest IN. Though, coverage and
intensity of showers/storms Friday onward is more uncertain as
guidance varies on where the waves will track and how previous
rounds of convection could alter the environment. Bottom line it
looks like another active period with some dry hours mixed in
at times. Regardless, temperatures through the extended period
(Thursday onward) are forecast to remain seasonable with highs
in the 80s and overnight lows in the 60s to around 70.

Yack

&&

.AVIATION /12Z TAFS THROUGH 18Z TUESDAY/...
Issued at 638 AM CDT Mon Jul 6 2026

Key aviation forecast messages:

- MVFR CIGs to scatter out by mid morning

An expansive area of low stratus across the lower Great Lakes
and the Ohio Valley managed to lift into the Chicago metro area
overnight and remains overhead this morning. The cloud layer is
showing signs of thinning along with the northern edge beginning
to sag south. Expect improvement back to VFR to occur over the
next couple of hours from north to south.

Winds remain light out of the NNE around 5-10 kt early this
morning. Expect winds to increase some out of the northeast by
mid morning to around 10-15 kt. Winds then ease and become
light and variable after sunset, potentially leaning NNW at
ORD/MDW under 5 kt through early Tuesday morning. An eventual
flop back to northeast may occur toward or just after the end of
the 30-hr TAF period paired with a reinforcing weak lake
breeze.

Petr

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...None.

&&

$$

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